Semiconductor device with shield for electromagnetic interference

ABSTRACT

A semiconductor device includes a first die embedded in a molding material, where contact pads of the first die are proximate a first side of the molding material. The semiconductor device further includes a redistribution structure over the first side of the molding material, a first metal coating along sidewalls of the first die and between the first die and the molding material, and a second metal coating along sidewalls of the molding material and on a second side of the molding material opposing the first side.

PRIORITY CLAIM AND CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.16/206,524, filed on Nov. 30, 2018, and entitled “Semiconductor Devicewith Shield for Electromagnetic Interference,” which is a divisional ofU.S. patent application Ser. No. 15/801,218, filed on Nov. 1, 2017, andentitled “Semiconductor Device with Shield for ElectromagneticInterference,” which claims priority to U.S. Provisional PatentApplication No. 62/527,879, filed on Jun. 30, 2017, which applicationsare hereby incorporated by reference in their entireties.

BACKGROUND

The semiconductor industry has experienced rapid growth due tocontinuous improvements in the integration density of a variety ofelectronic components (e.g., transistors, diodes, resistors, capacitors,etc.). For the most part, this improvement in integration density hascome from repeated reductions in minimum feature size, which allows morecomponents to be integrated into a given area. As the demand for evensmaller electronic devices has grown recently, there has grown a needfor smaller and more creative packaging techniques of semiconductordies.

An example of these packaging technologies is the Package-on-Package(POP) technology. In a PoP package, a top semiconductor packages isstacked on top of a bottom semiconductor package to allow high level ofintegration and component density. Another example is theMulti-Chip-Module (MCM) technology, where multiple semiconductor diesare packaged in one semiconductor package to provide semiconductordevices with integrated functionalities.

The high level of integration of advanced packaging technologies enablesproduction of semiconductor devices with enhanced functionalities andsmall footprints, which is advantageous for small form factor devicessuch as mobile phones, tablets and digital music players. Anotheradvantage is the shortened length of the conductive paths connecting theinteroperating parts within the semiconductor package. This improves theelectrical performance of the semiconductor device, since shorterrouting of interconnections between circuits yields faster signalpropagation and reduced noise and cross-talk.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1-2 illustrate cross-sectional views of a semiconductor die atvarious stages of fabrication, in accordance with some embodiments.

FIGS. 3 and 4 illustrate zoomed-in views of the semiconductor dieillustrated in FIG. 2, in accordance with some embodiments.

FIGS. 5, 6, 7A, 7B, 7C, and 8 illustrate various views of asemiconductor device at various stages of fabrication, in accordancewith some embodiments.

FIGS. 9-12 illustrate cross-sectional views of a semiconductor device atvarious stages of fabrication, in accordance with some embodiments.

FIGS. 13, 14, 15, 16, 17A, and 17B illustrate various views of asemiconductor device at various stages of fabrication, in accordancewith some embodiments.

FIG. 18 illustrates a cross-sectional view of an electrical system withelectromagnetic shield, in some embodiments.

FIG. 19 illustrates a flow chart of a method for forming a semiconductordevice, in some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the invention. Specificexamples of components and arrangements are described below to simplifythe present disclosure. These are, of course, merely examples and arenot intended to be limiting. For example, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed between the first and second features, such thatthe first and second features may not be in direct contact.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

FIGS. 1-2 illustrate cross-sectional views of a semiconductor die atvarious stages of fabrication, in accordance with some embodiments. InFIG. 1, a plurality of semiconductor dies 30 (see FIG. 2), which mayalso be referred to as integrated circuit dies or dies, are formed in asemiconductor wafer 30′. Tens, hundreds, or even more semiconductor dies30 may be formed in the semiconductor wafer 30′, and will be singulated(see FIG. 2) to form a plurality of individual semiconductor dies 30.

The wafer 30′ may include or be a semiconductor substrate, such assilicon, doped or undoped, or an active layer of asemiconductor-on-insulator (SOI) substrate. The semiconductor substratemay include other semiconductor materials, such as germanium; a compoundsemiconductor including silicon carbide, gallium arsenic, galliumphosphide, gallium nitride, indium phosphide, indium arsenide, and/orindium antimonide; an alloy semiconductor including SiGe, GaAsP, AlInAs,AlGaAs, GaInAs, GaInP, and/or GaInAsP; or combinations thereof. Othersubstrates, such as multi-layered or gradient substrates, may also beused. Devices, such as transistors, diodes, capacitors, resistors, etc.,may be formed in and/or on the semiconductor substrate and may beinterconnected by interconnect structures formed by, for example,metallization patterns in one or more dielectric layers on thesemiconductor substrate to form integrated circuits in the semiconductordies 30.

The semiconductor dies 30 further comprise contact pads 101, such asaluminum pads, to which external connections are made. The contact pads101 are on what may be referred to as respective active sides or frontsides of the semiconductor dies 30. A passivation film 103 is on thesemiconductor dies 30 and may be on portions of the contact pads 101.Openings are through the passivation film 103 to the contact pads 101.Die connectors 105, such as conductive pillars (for example, comprisinga metal such as copper), may extend into the openings through thepassivation film 103 and are mechanically and electrically coupled tothe respective contact pads 101. The die connectors 105 may be formedby, for example, plating, or the like. The die connectors 105electrically couple the respective integrated circuits of thesemiconductor dies 30. In the description hereinafter, the dieconnectors 105 may also be referred to as conductive pillars 105.

A dielectric material 107 is on the active sides of the semiconductordies 30, such as on the passivation film 103 and the die connectors 105.The dielectric material 107 laterally encapsulates the die connectors105. The dielectric material 107 may be a polymer such as PBO,polyimide, BCB, or the like; a nitride such as silicon nitride or thelike; an oxide such as silicon oxide, PSG, BSG, BPSG, or the like; or acombination thereof, and may be formed, for example, by spin coating,lamination, chemical vapor deposition (CVD), or the like. In the exampleof FIG. 1, a top surface of the dielectric material 107 extends furtheraway from the contact pads 101 than top surfaces of the conductivepillars 105.

Next, in FIG. 2, the front side of the wafer 30′ is attached to a tape108, such as a dicing tape, and is singulated along lines 31 to form aplurality of dies 30. A conductive coating 109, which comprises a copperlayer or other suitable material that is capable of providingelectromagnetic shielding to reduce electromagnetic interference (EMI)or reduce electromagnetic susceptibility (EMS), is formed over the backside (e.g., the side opposing the front side) of the dies 30 and overthe sidewalls of the dies 30. The conductive coating 109 may compriseone or more sublayers (see FIGS. 3 and 4), and at least one of thesublayers may comprise a suitable metal, such as copper. In someembodiments, the conductive coating 109 is conformally formed over theback sides and the sidewalls of the dies 30. Although not illustrated inFIG. 2, the conductive coating 109 may also be formed over the uppersurface of the tape 108. The conductive coating 109 may also be referredto as metal coating 109 in the description hereinafter.

FIGS. 3 and 4 illustrate zoomed-in views of an area 150 and an area 140of the semiconductor die 30 in FIG. 2, respectively, in someembodiments. The structures of the conductive coating 109 in FIGS. 3 and4 are merely non-limiting examples, and other numbers of sublayersand/or other structures are also possible and are fully intended to beincluded within the scope of the present disclosure.

As illustrated in FIG. 3, the conductive coating 109 comprises threesublayers, such as an interface layer 159, a barrier layer 157, and aconductive layer 154. The interface layer 159 is formed on the backsideand the sidewalls of the die 30, e.g., between the die 30 and thebarrier layer 157. The interface layer 159 may comprise a suitablematerial such as silicon oxide, and may be formed by thermaloxidization, CVD, physical vapor deposition (PVD), combinationstherefore, the like, or other suitable formation method. The interfacelayer 159 may act as an adhesion layer between the semiconductor die 30and a subsequently formed layer (e.g., 157), and may help thesubsequently formed layers (e.g., 157 and 109) to adhere to thesemiconductor die 30.

As illustrated in FIG. 3, the barrier layer 157 is formed over theinterface layer 159. The barrier layer 157 may be formed to prevent orreduce diffusion of the material (e.g., copper) of the metal coating 109into, e.g., the substrate of the semiconductor dies 30. In someembodiments, the barrier layer 157 comprises titanium nitride, althoughother materials, such as tantalum nitride, titanium oxide, tantalumoxide, titanium, tantalum, or the like may alternatively be utilized.The barrier layer 157 may be formed using a CVD process, such asplasma-enhanced CVD (PECVD). However, other alternative processes, suchas sputtering or metal organic chemical vapor deposition (MOCVD), atomiclayer deposition (ALD), may alternatively be used.

Next, the conductive layer 154 is formed over the barrier layer 157. Theconductive layer 154 may comprise a suitable metal such as copper, andmay have a thickness between about 3 μm and about 5 μm, such as about 3μm, although other dimensions are also possible. Suitable depositionmethods, such as sputtering, spraying, or plating, may be used to formthe conductive layer 154. In some embodiments, a seed layer (not shown)is formed over the barrier layer 157, then the conductive layer 154 isformed over the seed layer using a plating process.

In embodiments where the interface layer 159 (e.g., silicon oxide) isformed by thermal oxidization of the substrate (e.g., silicon) of thesemiconductor die 30, the conductive coating 109 in the area 140 of thesemiconductor die 30 may have a different structure than the conductivecoating 109 in the area 150, as illustrated in FIG. 4. The conductivecoating 109 in the area 140 corresponds to portions of the conductivecoating 109 disposed along sidewalls of the dielectric material 107 ofthe die 30. Since the thermal oxidization process does not generate,e.g., silicon oxide, over the dielectric material 107, the interfacelayer 159 illustrated in FIG. 3 is not formed in the area 140.Therefore, the conductive coating 109 in the area 140 comprises thebarrier layer 157 and the conductive layer 154, both of which areelectrically conductive layers.

FIGS. 5, 6, 7A, 7B, 7C, and 8 illustrate various views of asemiconductor device 200 at various stages of fabrication, in accordancewith some embodiments. In FIG. 5, the die 30 with the metal coating 109as illustrated in FIG. 2 is attached to a carrier 120 by an adhesivelayer 121, with the front side of the die 30 facing away from thecarrier 120. A second die 40, which may be a die having differentfunctionalities from the die 30, is also attached to the carrier 120with the front side of the die 40 facing away from the carrier 120.

The carrier 120 may be made of a material such as silicon, polymer,polymer composite, metal foil, ceramic, glass, glass epoxy, berylliumoxide, tape, or other suitable material for structural support. Theadhesive layer 121 is deposited or laminated over the carrier 120, insome embodiments. The adhesive layer 121 may be photosensitive and maybe easily detached from the carrier 120 by shining, e.g., anultra-violet (UV) light on the carrier 120 in a subsequent carrierde-bonding process. For example, the adhesive layer 121 may be alight-to-heat-conversion (LTHC) coating made by 3M Company of St. Paul,Minn.

The second die 40 may be formed in similar processing steps as those ofthe die 30 described above, but without the metal coating 109. The die40 has contact pads 111 in a passivation film 113, conductive pillars115 coupled to the contact pads 111, and a dielectric material 117 overthe conductive pillars 115. The contact pads 111, the passivation film113, the conductive pillars 115, and the dielectric material 117 of thedie 40 may comprise a same or similar material as the contact pads 101,the passivation film 103, the conductive pillars 105, and the dielectricmaterial 107 of the die 30, respectively, and may be formed using a sameor similar method. Details are thus not repeated.

In some embodiments, the die 30 is an radio frequency (RF) die, and thedie 40 is a digital logic die. Since an RF die (e.g., the die 30) may bemore susceptible to electromagnetic interference than a logic die (e.g.,the die 40), the die 30 has the metal coating 109 to shield the die 30from EMI. The metal coating 109 may also contain (e.g., limit) the EMinterference produced by the die 30, such that the EM interferenceproduced by the die 30 causes little or no inference for other dies(e.g., the die 40). The die 40 is free of the metal coating 109 in theillustrated embodiment. In other embodiments, both the die 30 and thedie 40 have the metal coating 109, and the die 40 is formed followingsimilar processing steps as illustrated in FIGS. 1-4.

Next, a molding material 123 is formed over the carrier 120 and aroundthe dies 30 and 40. The molding material 123, as deposited, may extendover the upper surfaces of the dies 30 and 40. The molding material 123may comprise an epoxy, an organic polymer, a polymer with or without asilica-based or glass filler added, a polyamide, or other materials, asexamples. In some embodiments, the molding material 123 comprises aliquid molding compound (LMC) that is a gel type liquid when applied.The molding material 123 may also comprise a liquid or solid whenapplied. The molding material 123 may be molded using, for example,compressive molding, transfer molding, or other methods.

Once deposited, the molding material 123 may be cured by a curingprocess. The curing process may comprise heating the molding material123 to a predetermined temperature for a predetermined period of time,using an anneal process or other heating process. The curing process mayalso comprise an ultra-violet (UV) light exposure process, an infrared(IR) energy exposure process, combinations thereof, or a combinationthereof with a heating process. Alternatively, the molding material 123may be cured using other methods. In some embodiments, a curing processis not performed.

Next, a planarization process, such as a chemical mechanical polish(CMP), may be performed to remove upper portions of the molding material123, and to expose the conductive pillars 105 of the die 30 and toexpose the conductive pillars 115 of the die 40. The planarizationprocess achieves a substantially coplanar upper surface between theconductive pillars (e.g., 105, 115), the dielectric materials (e.g.,107, 117), and the molding material 123. The planarization process mayremove upper portions of the dielectric materials 107/117 and mayfurther remove top portions of the conductive pillars 105/115.

Next, in FIG. 6, a redistribution structure 130 is formed over the die30, the die 40, and the molding material 123. The redistributionstructure 130 comprises conductive features such as one or more layersof conductive lines 131 and vias 133 formed in one or more dielectriclayers 132. In some embodiments, the one or more dielectric layers 132are formed of a polymer, such as polybenzoxazole (PBO), polyimide,benzocyclobutene (BCB), or the like. In other embodiments, thedielectric layer 104 is formed of a nitride such as silicon nitride; anoxide such as silicon oxide, phosphosilicate glass (PSG), borosilicateglass (BSG), boron-doped phosphosilicate glass (BPSG), or the like; orthe like. The one or more dielectric layers 132 may be formed by anyacceptable deposition process, such as spin coating, chemical vapordeposition (CVD), laminating, the like, or a combination thereof.

In some embodiments, the conductive features of the redistributionstructure 130 comprise conductive lines 131 and/or conductive via 133formed of a suitable conductive material such as copper, titanium,tungsten, aluminum, or the like. The conductive features may be formedby, e.g., forming openings in the dielectric layer 132 to exposeunderlying conductive features, forming a seed layer over the dielectriclayer 132 and in the openings, forming a patterned photoresist with adesigned pattern over the seed layer, plating (e.g., electroplating orelectroless plating) the conductive material in the designed pattern andover the seed layer, and removing the photoresist and portions of seedlayer on which the conductive material is not formed.

The redistribution structure 130 is electrically coupled to the dies 30and 40. Conductive pads 137, which may be under bump metallurgy (UBM)structures, may be formed over and electrically coupled to theredistribution structure 130. As illustrated in FIG. 6, at least oneconductive line 131A of the redistribution structure 130 extends to andis exposed at a sidewall of the redistribution structure 130. Theconductive line 131A may be used to connect to a subsequently formedconductive layer 119 (see FIG. 8) and to ground the conductive layer119.

As illustrated in FIG. 6, the metal coating 109 of the die 30 iselectrically coupled to the conductive line 131A through, e.g., a via133A. The conductive line 131A is electrically coupled to a groundcontact pad 101A (e.g., a contact pad configured to be connected to anelectrical ground), such as the leftmost or the rightmost contact pad ofthe die 30 in FIG. 6, in some embodiments. The ground contact pad 101Ais coupled to the electrical ground (not shown) through an externalconnector 143 (e.g., see 143A in FIG. 8) attached to a conductive pad137A, in some embodiments. Therefore, the metal coating 109 of the die30 is grounded to provide shielding from electromagnetic interferencefor the die 30. The metal coating 109 may also prevent or reduce theelectromagnetic inference generated by the die 30 from interfering withother dies (e.g., the die 40) in the system.

FIG. 7A is a cross-sectional view of a portion of the semiconductordevice 200 showing details of the grounding of the metal coating 109 asillustrated in FIG. 6, in an embodiment. As illustrated in FIG. 7A, theground contact pad 101A is coupled to a conductive pillar 105A, whichconductive pillar 105A may be formed to have an extension portion thatextends from the ground contact pad 101A to a location close to the edge(e.g., sidewalls) of the die 30, and therefore, close to the metalcoating 109 in order to facilitate electrical connection with the metalcoating 109. The via 133A, which may be formed in a first via layer(e.g., a via layer of the redistribution structure 130 closest to thedie 30) of the redistribution structure 130, connects the conductivepillar 105A to the metal coating 109.

FIG. 7B is a cross-sectional view of the semiconductor device 200 inFIG. 7A along cross-section A-A. The cross-section A-A is across the via133A, thus the conductive pillar 105A and the ground contact pad 101Aare not visible in the plane of the cross-section A-A, and thus, areshown in phantom in FIG. 7B. For simplicity, not all layers and not allcomponents of the semiconductor device 200 are shown in the top view ofFIG. 7B. FIG. 7A is a cross-sectional view of portions of thesemiconductor device 200 in FIG. 7B along the cross-section B-B.

As illustrated in FIG. 7B, the conductive coating 109 is around thesidewalls of the die 30. The contact pad 101 and the ground contact pad101A shown in FIG. 7A are illustrated on a same line as thecross-section B-B in FIG. 7B. Also illustrated in FIG. 7B are the via133 above the contact pad 101 in FIG. 7A, and the conductive pillar 105Acoupled to the ground contact pad 101A in FIG. 7A. Furthermore, anadditional ground contact pad 101B, which is formed in the dielectricmaterial 107 and electrically connected to the ground contact pad 101Aby a conductive feature 105′ (e.g., a conductive line formed in thedielectric material 107), is shown in FIG. 7B. Since the contact pad101B and the conductive feature 105′ are not on the line of thecross-section B-B, they are not visible in the cross-sectional view ofFIG. 7A.

In the illustrated embodiment of FIG. 7B, the via 133A is formeddifferently from the other vias (e.g., the vias 133) of theredistribution structure 130 to facilitate the electrical connectionbetween the via 133A and the metal coating 109. In particular, the via133A may have an elongated shape instead of, e.g., a circular shape, ina top view. The elongated shape of the via 133A has a larger dimensionalong the direction B-B than a dimension along a direction perpendicularto the direction B-B, in some embodiments. The elongated shape of thevia 133A provides a large tolerance for inaccuracies of thephotolithography process used to form the pattern for the via 133A. Forexample, the elongated shape makes it easier to achieve a reliableelectrical connection between the via 133A and the metal coating 109,even if the actual location of the via 133A is shifted to the left or tothe right by a little (e.g., by a few nanometers) compared with anintended location (e.g., designed location).

In FIG. 7B, the via 133A is shown to have an oval shape, although otherelongated shapes, such as a rectangular shape, a race track shape (e.g.,a rectangle with semi-circular shapes on opposing sides of therectangle, see 133B), and other suitable shapes may also be used. Asecond via 133B, which is not visible in the cross-sectional view ofFIG. 7A, connects the conductive feature 105′ with the metal coating109. The second via 133B is illustrated to have the race track shape asan example. In other embodiments, the second via 133B may have the sameshape (e.g., oval shape) as the first via 133A, or may have othersuitable shapes. Therefore, in the example of FIG. 7B, the metal coating109 is grounded by the via 133A and the via 133B, thus furtherincreasing the reliability of the grounding of the metal coating 109.

FIG. 7C illustrates the cross-sectional view of the semiconductor device200 shown in FIGS. 7A and 7B, but along cross-section B1-B1 of FIG. 7B.As illustrated in FIG. 7C, the via 133B electrically connects theconductive feature 105′ with the metal coating 109. Since the conductivefeature 105′ is coupled to the ground contact pads 101A and 101B (seeFIG. 7B), the metal coating 109 is grounded.

Next, in FIG. 8, external connectors 143 are formed over the conductivepads 137, the carrier 120 is de-bonded, and a conductive layer 119 isformed over sidewalls and an upper surface of the molding material 123.In some embodiments, the external connectors 143 are conductive bumpssuch as controlled collapse chip connection (C4) bumps or ball gridarray (BGA) bumps, and may comprise a material such as tin, or othersuitable materials, such as silver or copper. In an embodiment in whichthe external connectors 143 are tin solder bumps, the externalconnectors 143 may be formed by initially forming a layer of tin throughany suitable method such as evaporation, electroplating, printing,solder transfer, or ball placement. Once a layer of tin has been formedon the conductive pads 137, a reflow is performed in order to shape thematerial into the desired bump shape.

However, as one of ordinary skill in the art will recognize, while theexternal connectors 143 have been described above as C4 bumps or BGAbumps, these are merely intended to be illustrative and are not intendedto limit the embodiments. Rather, any suitable type of externalcontacts, such as microbumps, copper pillars, a copper layer, a nickellayer, a lead free (LF) layer, an electroless nickel electrolesspalladium immersion gold (ENEPIG) layer, a Cu/LF layer, a Sn/Ag layer, aSn/Pb, combinations of these, or the like, may alternatively beutilized. Any suitable external connector, and any suitable process forforming the external connectors, may be utilized for the externalconnectors 143, and all such external connectors are fully intended tobe included within the scope of the embodiments.

In some embodiments, the carrier 120 is de-bonded after the externalconnectors 143 are formed on the conductive pads 137. For example, thestructure shown in FIG. 6, with the external connectors 143 formed, isflipped upside down, and the external connectors 143 are attached to atape (e.g., a dicing tape, not shown). The tape is soft and has athickness larger than the height of external connectors 143, in someembodiments. The semiconductor device 200 may therefore be pressed ontothe tape such that the external connectors 143 are embedded in (e.g.,pressed into) the tape. This may prevent electrical short of thesemiconductor device 200 in a subsequent processing step to form theconductive layer 119.

Next, the carrier 120 is de-bonded by a suitable method such as chemicalwet etching, plasma dry etching, mechanical peel-off, CMP, mechanicalgrinding, thermal bake, laser scanning, or wet stripping, as examples.In some embodiments, the carrier 120 is a glass carrier and is de-bondedby a shining a light on the carrier 120. For example, ultraviolet (UV)light emitted by an excimer laser may go through the glass carrier andis absorbed near the glass/adhesive interface. The ultraviolet lightinitiates a photochemical process that breaks the chemical bonds in theadhesive layer 121. As a result, the glass carrier 120 is easilyremoved.

In other embodiments, the carrier de-bonding may be performed before theexternal connectors 143 are formed, e.g., by attaching theredistribution structure 130 to a tape and then removing the carrier120. After the carrier 120 is de-bonded, the semiconductor device 200 isremoved from the tape and is flipped upside down, and the externalconnectors 143 are formed over the conductive pads 137. These and othervariations of the processing steps are fully intended to be includedwithin the scope of the present disclosure. In embodiments wheremultiple semiconductor devices 200 are formed at the same time, asingulation process (not shown) is performed to form a plurality ofindividual semiconductor devices 200.

Next, the conductive layer 119, which may comprise copper or othersuitable material for electromagnetic interference protection, is formedover the semiconductor device 200 using, e.g., plating, sputtering,spraying, or other suitable formation method. A thickness of theconductive layer 119 may range from about 3 μm to about 5 μm, such as 3μm, although other dimensions are also possible.

As illustrated in FIG. 8, the conductive layer 119 is formed on thebackside of the dies 30/40 (e.g., over the adhesive layer 121) and alongthe sidewalls of the molding material 123. Since the conductive layer119 (may also be referred to as a metal coating 119) does not contactthe substrate of the dies 30 and 40, diffusion (e.g., copper diffusion)of the material of the conductive layer 119 may not be a concern, andtherefore, a barrier layer similar to the barrier layer 157 (see FIG. 3)may be omitted in the formation of the conductive layer 119. Therefore,unlike the conductive coating 109 (see FIG. 3), which has an underlyingbarrier layer 157 and an underlying interface layer 159, the conductivelayer 119 may be formed over the sidewalls of the molding material 123and over the adhesive layer 121 without a barrier layer between theconductive layer 119 and the dies 30/40, in some embodiments. In someembodiments, the conductive layer 119 has a single-layer structure andis formed of a suitable material such as copper, in which case theconductive layer 119 (e.g., copper) directly contacts, e.g., the moldingmaterial 123, the adhesive layer 121, and the one or more dielectriclayers 132. In some embodiments, depending on, e.g., the material of theconductive layer 119, there might be an interface layer between theconductive layer 119 and, e.g., the molding material 123, the adhesivelayer 121, and the one or more dielectric layers 132.

As illustrated in FIG. 8, the conductive layer 119 is grounded bycoupling to the conductive line 131A, which is exposed at the sidewallof the redistribution structure 130, in some embodiments. FIG. 8 alsoillustrates a via 133A of the redistribution structure 130, which via133A is coupled to the conductive coating 109 over the die 30 (similarto FIGS. 7A and 7B). Therefore, the conductive layer 119 and theconductive coating 109 are electrically grounded by coupling to one ormore ground contact pads 101A, which are grounded by, e.g., one or moreexternal connectors 143A connected to an electrical ground.

FIGS. 9-12 illustrate cross-sectional views of a semiconductor device300 at various stages of fabrication, in accordance with someembodiments. Similar numerals in FIGS. 9-12 represent similar parts asin FIGS. 3-8, thus details are not repeated. As illustrated in FIG. 9,the semiconductor dies 30 and 40 are each attached to the carrier 120via an adhesive layer 121. Note that in the example of FIG. 9, the dies30 and 40 are not coated with the conductive coating 109 prior to beingattached to the carrier 120. The dies 30 and 40 may be of the same type(e.g., having a same functionality) or of different types (e.g., havingdifferent functionalities). After the dies 30 and 40 are attached to thecarrier 120, the conductive coating 109 is conformally formed over thedie 30, the die 40, and the carrier 120.

In FIG. 9, portions of the conductive coating 109 in regions 150′, e.g.,the portions of the conductive coating 109 contacting the semiconductorsubstrate of the dies 30 and 40, may have a same structure asillustrated in FIG. 3. In addition, other portions of the conductivecoating 109, e.g., the portions of the conductive coating 109 over thedielectric material 107, over the adhesive layer 121 and over thecarrier 120 may have a same structure as illustrated in FIG. 4.

Next, as illustrated in FIG. 10, the molding material 123 is formed overthe carrier 120 and around the dies 30/40. A curing process may beperformed to cure the molding material 123. Next, the (cured) moldingmaterial 123 is planarized, e.g., by a CMP process, to expose theconductive pillars 105 of the die 30 and the conductive pillars 115 ofthe die 40. The planarization process removes portions of the conductivecoating 109 over the front sides of the dies 30 and 40. Therefore, inthe cross-sectional view of FIG. 10, after the planarization, theremaining portions of the conductive coating 109 have a U-shape betweenthe dies 30 and 40, and have an L-shape proximate the exterior sidewalls(e.g., sidewalls proximate edges of the semiconductor device 300) of thedies 30 and 40.

Next, in FIG. 11, the redistribution structure 130 is formed over thefront sides of the dies 30 and 40, and are electrically coupled to thedies 30 and 40. The redistribution structure 130 comprises conductivelines 131 and vias 133. Conductive pads 137, which may be UBMstructures, are formed over the upper surface of the redistributionstructure 130. At least one conductive line 131A of the redistributionstructure 130 is exposed at the sidewall of the redistribution structure130.

In the illustrated example of FIG. 11, the conductive coating 109 isgrounded through connection to the redistribution structure 130 (e.g.,through the vias 133A) and to the ground contact pad 101A, similar tothe embodiments illustrated in FIGS. 7A and 7B. The conductive coating109 may also be electrically coupled to a ground contact pad 111A of thedie 40 through the redistribution structure 130, as illustrated in FIG.11.

Next, as illustrated in FIG. 12, the external connectors 143 are formedover the conductive pads 137, the carrier 120 is de-bonded, and theconductive layer 119 is formed over the backsides of the dies 30/40(e.g., over the adhesive layer 121) and over the sidewalls of themolding material 123. The conductive layer 119 is grounded by couplingto the conductive line 131A exposed by the sidewall of theredistribution structure 130, in some embodiments.

In some embodiments, the conductive layer 119 is conformally formed, andmay have a thickness equal to the thickness of the conductive coating109, which is also conformally formed. Note that in regions 119D, theconductive layer 119 and the conductive coating 109 merge to form aconductive layer (e.g., copper) that is thicker (e.g., about twice asthick) than the conductive layer 119 or the conductive coating 109 inregions other than the regions 119D. For example, a thickness of the(merged) conductive layer between the dies 30 and 40 may be twice of athickness of the conductive coating 109 along the sidewalls of the dies30 and 40. As another example, a thickness of the (merged) conductivelayer between the dies 30 and 40 may be twice of a thickness of theconductive layer 119 along the sidewalls of the molding material 123 orover the adhesive layer 121. In the cross-sectional view of FIG. 12, theconductive layer 119 and the conductive coating 109 form U-shapesbetween the dies 30 and 40 and proximate exterior sidewalls of the dies30 and 40. In other embodiments, the conductive layer 119 and theconductive coating 109 have different thicknesses.

FIGS. 13, 14, 15, 16, 17A, and 17B illustrate various views of asemiconductor device 400 at various stages of fabrication, in accordancewith some embodiments. In FIG. 13, a dielectric film, such as a photosensitive dielectric layer, is formed over the carrier 120. Thedielectric film is patterned using, photolithography and/or etchingprocess to form structures 151 and 153. In some embodiments, due to thephotolithography process used, a width of the structures 151 (or 153) inthe cross-sectional view of FIG. 13 decreases as the structures 151 (or153) extend away from the carrier 120. For example, the structures 151and 153 have trapezoidal cross-sections, as illustrated in FIG. 13. Moredetails of the structures 151/153 are described hereinafter.

In FIG. 14, a conductive layer 155, such as copper or other suitablematerial capable of providing EMI shielding and/or protection, is formedover the structure shown in FIG. 13. The conductive layer 155 maycomprise a metal (e.g., copper), and may be formed by sputtering,spraying, plating, or other suitable method. A thickness of theconductive layer 155 is between about 3 μm and about 5 μm, in someembodiments, although other dimensions are also possible.

In some embodiments, the structures 151 are dielectric structures.Referring temporarily to FIG. 17B, which is a cross-sectional view ofthe semiconductor device 400 along cross-section E-E in FIG. 17A, thestructures 151 may comprise dielectric structures that surround the die30 and/or the die 40. The structures 151 may be a continuous dielectricstructure that encircles the die 30 and/or the die 40, as shown in FIG.17B, in some embodiments. In other embodiments, the structures 151 maycomprise multiple discrete segments (e.g., segments that have gaps inbetween, not shown) of dielectric structures that encircle the die 30and/or the die 40. Although the structures 151 are made of a dielectricmaterial, after being coated by the conductive layer 155, the coatedstructures 151 form an electromagnetically shielding structure aroundthe semiconductor dies 30/40 to prevent or reduce EMI (see FIGS. 17A and17B).

Referring back to FIG. 14, in some embodiments, the structures 153 aredielectric structures and have a substantially cylindrical shape or atruncated cone shape. After being coated with the conductive layer 155,each coated structure 153 forms a conductive via, in some embodiments.Referring temporarily to FIG. 17B, the coated structure 153 includes asolid dielectric core (e.g., the structure 153) with the conductivelayer 155 coated on the exterior sidewalls of the dielectric core, inaccordance with some embodiments.

Referring now to FIG. 15, the semiconductor dies 30 and 40 are attachedto the carrier 120 by the adhesive layer 121. Next, the molding material123 is deposited, cured if needed, and then planarized to expose theconductive pillars 105/115 of the dies 30/40. The planarization processalso removes the top portions of the conductive layer 155 (e.g.,portions of the conductive layer 155 over upper surfaces of thestructures 151/153 distal the carrier 120) and exposes the dielectricmaterial of the structures 151 and 153, as illustrated in FIG. 15.

Next, in FIG. 16, the redistribution structure 130 is formed over thefront sides of the dies 30 and 40. The redistribution structure 130 maycomprise conductive lines 131 and vias 133. Conductive pads 137 areformed over and electrically coupled to the redistribution structure130. A illustrated in FIG. 16, the conductive layer 155 is grounded byelectrical connection to the redistribution structure 130 through, e.g.,the vias 133A, which redistribution structure 130 comprises conductivelines and/or vias that are coupled to the ground contact pads 101A/110A,which in turn are coupled to one or more external connectors 143 (seeFIG. 17B) that are electrically grounded. In some embodiments, aconductive line 131A of the redistribution structure 130 is exposed atthe sidewall of the redistribution structure 130.

Next, in FIG. 17A, the external connectors 143 are formed, the carrier120 is de-bonded, and the exposed surface (e.g., the surface proximatethe back side of the dies 30/40) of the semiconductor device 400 afterthe carrier de-bonding is recessed by a suitable grinding process and/oran etching process, such as CMP. In some embodiments, the recessingprocess removes portions of the conductive layer 155 over the back sidesof the dies 30 and 40. The recessing process may also remove theadhesive layer 121. Therefore, after the recessing process, thedielectric material of the structures 151/153 proximate the back sidesof the dies 30 and 40 is exposed, in some embodiments.

Next, another redistribution structure 160 is formed over the back sideof the dies 30 and 40, and may be formed using the same or similarformation methods as the redistribution structure 130. Theredistribution structure 160 includes conductive lines 161 and vias 163that are electrically coupled to the remaining portions of theconductive layer 155, such as portions of the conductive layers 155 overthe sidewalls of the structure 151 and over the sidewalls of thestructure 153. In some embodiments, conductive lines 161′ of theredistribution structure 160 comprise ground planes. The ground planes(e.g., 161′) and the structures 151 with conductive coating 155 form anEMI shield around and over the dies 30 and 40. The EMI shield reducesthe EM interference for the dies 30 and 40. The EM shield may alsocontain, and thus, reduce the EM inference generated by the dies 30 and40.

As illustrated in FIG. 17A, openings 164 are formed in theredistribution structure 160. The openings 164 may be formed by laserdrilling, etching, or other suitable method. The openings 164 exposesportions of the conductive lines 161, which are electrically coupled tothe conductive layer 155 over the structures 153 to electrically couplethe redistribution structure 130 with the redistribution structure 160,in some embodiments. The exposed portion of the conductive lines 161also provides access for electrical connection at the back sides of thedies 30 and 40. For example, another semiconductor device (not shown)may be placed above the semiconductor device 400, and be electricallyand mechanically coupled to the exposed portions of the conductive lines161 to form a PoP package.

FIG. 17B is a cross-sectional view of the semiconductor device 400 ofFIG. 17A along cross-section E-E, and FIG. 17A is the cross-sectionalview of the semiconductor device 400 in FIG. 17B along cross-sectionF-F. The molding material 123 is not shown in FIG. 17B for clarity. Asillustrated in FIG. 17B, the structures 151 comprise a continuousstructure around the dies 30 and 40, and the conductive layer 155 isformed on opposing sidewalls of the structures 151. FIG. 17B alsoillustrates the structures 153, which may have circular cross-sections,and the conductive layer 155 that are formed over the sidewalls of thestructures 153.

FIG. 17B is merely a non-limiting example of the structures 151 and thestructure 153, and other shapes and/or cross-sections for the structure151 and the structure 153 are also possible and are fully intended to beincluded within the scope of the present disclosure. For example, thestructure 151 may include multiple discrete (e.g., separate) segments ofdielectric regions that collectively surround the dies 30 and 40. Asanother example, the cross-section of the structure 153 may have othersuitable shapes such as an oval shape, a square shape or a rectangularshape.

FIG. 18 shows an electrical system 500 with EMI protection. Theelectrical system 500 comprises a semiconductor device 510, which issimilar to the semiconductor device 200 in FIG. 8, but with metalcoatings 509 for both the die 30 and the die 40. The metal coating 509may be similar to the metal coating 109 in FIG. 8. The semiconductordevice 510 further has a conductive layer 519, which may be similar tothe conductive layer 119 of FIG. 8. The electrical system 500 furthercomprises a substrate 520, which may be a printed circuit board (PCB)with conductive traces (e.g., 521/523/525) and conductive pads (e.g.,527) formed therein and/or thereon. FIG. 18 further illustrates aconnector 530 (e.g., an RF connector) that is mechanically andelectrically coupled to the substrate 520. As illustrated in FIG. 18,the connector 530 has a signal terminal 533 and a ground terminal 531.The signal terminal 533 may be a terminal for carrying an RF signal(e.g., an RF input signal to be processed by the electrical system 500),the ground terminal 531 may be electrically grounded. In someembodiment, the ground terminal 531 is a metal shell or a metal mesharound the signal terminal 533 to provide good EMI protection.

As illustrated in FIG. 18, two external connectors 541 and 545 of thesemiconductor device 510 are electrically grounded, and are connected toconductive lines 521 and 525 of the substrate 520, respectively, whichconductive lines 521 and 525 are coupled to the ground terminal 531 ofthe connector 530. The signal terminal 533 of the connector 530 isconnected to an external connector 543 of the semiconductor device 510,which external connector 543 is for connection with a signal (e.g., anRF input signal from the connector 530). In some embodiments, theconductive lines 521 and 525 are ground planes, and the conductive line523 carrying the RF signal is disposed between the ground planes 521 and525. The system 500 has excellent EMI protection. For example, there isdouble EMI shielding (e.g., conductive coatings 509 and 519) for thesemiconductor device 510. In addition, the ground planes 521 and 525disposed above and below the conductive line 523 provide enhanced EMIinsulation for the conductive line 523 carrying an RF signal. Thesefeatures, coupled with the EMI shielding for the signal terminal 533offered by the ground terminal 531, provide good EMI protectionthroughout the signal chain of the electrical system 500, thus offeringexcellent robustness against EM interference.

Variations to the disclosed embodiments are possible and fully intendedto be included within the scope of the present disclosure. For example,two semiconductor dies (e.g., 30 and 40) are used in the semiconductordevice as examples. However, more or less than two dies may be used inthe semiconductor device formed. As another example, the shape of thestructure 151 (see FIG. 17B) may include two separate rings, with eachof the rings surrounding one of the dies 30/40. In addition, each of thetwo separate rings may be a continuous ring, or a ring formed bymultiple discrete segments. As yet another example, the number and thelocation of the structures 153 may be changed from those illustrated inFIG. 17B without departing from the spirit of the present disclosure.

FIG. 19 illustrates a flow chart of a method for forming a semiconductordevice, in accordance with some embodiments. It should be understoodthat the embodiment methods shown in FIG. 19 is an example of manypossible embodiment methods. One of ordinary skill in the art wouldrecognize many variations, alternatives, and modifications. For example,various steps as illustrated in FIG. 19 may be added, removed, replaced,rearranged and repeated.

Referring to FIG. 19, at step 1010, a first die is attached to acarrier, where contact pads on a front side of the first die face awayfrom the carrier. At step 1020, a molding material is formed over thecarrier and around the first die. At step 1030, a redistributionstructure is formed over a first side of the molding material distal thecarrier, where the redistribution structure comprises conductive lineselectrically coupled to the first die, where a first conductive featureof the redistribution structure is exposed at a sidewall of theredistribution structure. At step 1040, the carrier is de-bonded. Atstep 1050, a first conductive coating is formed along sidewalls of themolding material and a second side of the molding material opposing thefirst side, where the first conductive coating is electrically connectedto the first conductive feature of the redistribution structure.

Disclosed embodiments have many advantages. The metal coating 109 overthe semiconductor dies 30/40 and/or the metal coating 119 over theexterior surface of the molding material 123 provide EMI protection, andtherefore, the semiconductor device formed has better performanceagainst EM interference. The disclosed EMI protection structures can beeasily integrated with existing manufacturing flow, with little or noextra spaced needed to accommodate the EMI protection structures, thusallowing for low cost packages with small sizes and enhanced EMIprotection. Features such as the elongated via 133A (see FIG. 7B) forconnection to the metal coating (e.g., 109) allows for larger errormargin for the photolithography process, and provide more reliablegrounding of the metal coating. The disclosed EMI protection/insulationstructure also simplifies the analysis of the EM performance of thesemiconductor devices formed, and as a result, simulation time foranalyzing the EM performance of the semiconductor devices is greatlyreduced, which in turn reduces the design cycle and reduces the productto market time. Analysis shows that a near perfect Faraday cage may beachieved by connecting the metal coating (e.g., 109) with electricalground at the first via layer (e.g., via 133A) of the redistributionstructure. The double metal coating structure (e.g., 109 and 119)achieves improved EM performance by using the outer metal coating (e.g.,119) to further reducing the EM interference reaching the semiconductordevice.

In an embodiment, a semiconductor device includes a first die embeddedin a molding material, where contact pads of the first die are proximatea first side of the molding material; a redistribution structure overthe first side of the molding material; a first metal coating alongsidewalls of the first die and between the first die and the moldingmaterial; and a second metal coating along sidewalls of the moldingmaterial and on a second side of the molding material opposing the firstside. In an embodiment, the first metal coating and the second metalcoating are electrically connected to a ground contact. In anembodiment, the redistribution structure includes a via that iselectrically coupled to the first metal coating. In an embodiment, thevia has a first dimension along a first direction and a second dimensionalong a second direction perpendicular to the first direction, thesecond dimension being smaller than the first dimension. In anembodiment, the first die has a plurality of conductive pillars coupledto respectively ones of the contact pads, where at least one of theplurality of conductive pillars is electrically coupled to the firstmetal coating. In an embodiment, an upper surface of the plurality ofthe conductive pillars distal the contact pads is level with the firstside of the molding material. In an embodiment, the second metal coatingis electrically coupled to a conductive line of the redistributionstructure, where the conductive line is exposed at a sidewall of theredistribution structure. In an embodiment, the semiconductor devicefurther includes a second die embedded in the molding material andlaterally spaced from the first die, where contact pads of the seconddie are electrically coupled to the redistribution structure. In anembodiment, sidewalls of the second die are free of a metal coating. Inan embodiment, the first die and the second die have differentfunctionalities. In an embodiment, the first metal coating extendscontinuously from the sidewalls of the first die to sidewalls of thesecond die.

In an embodiment, a semiconductor device includes a first die in amolding layer; a first redistribution structure on a first side of themolding layer and including conductive lines electrically coupled tocontact pads of the first die; a second redistribution structure on asecond side of the molding layer opposing the first side; a firstconductive structure in the molding layer and laterally spaced from thefirst die, where the first conductive structure includes a firstdielectric region around the first die; and conductive coatings onopposing sides of the first dielectric region; and a via in the moldinglayer, where the via is coupled to a first conductive line of the firstredistribution structure and a second conductive line of the secondredistribution structure. In an embodiment, the via includes a seconddielectric region; and a second conductive coating on sidewalls of thesecond dielectric region. In an embodiment, the via is between the firstdie and the first conductive structure. In an embodiment, the firstconductive structure is electrically coupled to at least one conductiveline of the first redistribution structure and at least one conductiveline of the second redistribution structure. In an embodiment, thesecond redistribution structure includes a ground plane, and the firstconductive structure is electrically coupled to the ground plane.

In an embodiment, a method includes attaching a first die to a carrier,where contact pads on a front side of the first die face away from thecarrier; forming a molding material over the carrier and around thefirst die; forming a redistribution structure over a first side of themolding material distal the carrier, where the redistribution structureincludes conductive lines electrically coupled to the first die, where afirst conductive feature of the redistribution structure is exposed at asidewall of the redistribution structure; de-bonding the carrier; andforming a first conductive coating along sidewalls of the moldingmaterial and a second side of the molding material opposing the firstside, where the first conductive coating is electrically connected tothe first conductive feature of the redistribution structure. In anembodiment, the method further includes forming a second conductivecoating over sidewalls and a back side of the first die before attachingthe first die to the carrier. In an embodiment, the first die hasconductive pillars over and electrically coupled to the contact pads ofthe first die, where a first one of the conductive pillars extends to anedge of the first die, where the first one of the conductive pillars iselectrically coupled to the second conductive coating through a via ofthe distribution structure. In an embodiment, a via of theredistribution structure is electrically coupled to the secondconductive coating. In an embodiment, the via is formed to have an ovalshape in a top view.

In an embodiment, a method includes forming a first dielectric structureon a carrier; forming a conductive layer over the first dielectricstructure; attaching a first die to the carrier, where the first die islaterally separated from the first dielectric structure; encapsulatingthe first die and the first dielectric structure in a molding layer;forming a first redistribution structure on a first side of the moldinglayer, the first redistribution structure comprising conductive lineselectrically coupled to contact pads of the first die and coupled to theconductive layer over the first dielectric structure; de-bonding thecarrier; and forming a second redistribution structure on a second sideof the molding layer opposing the first side, the second redistributionstructure comprising conductive lines electrically coupled to theconductive layer over the first dielectric structure. In an embodiment,the method further includes, after encapsulating the first die and thefirst dielectric structure and before forming the first redistributionstructure, recessing the molding layer from the first side of themolding layer, where the recessing exposes conductive pillars of thefirst die and a first surface of the first dielectric structure. In anembodiment, the method further includes after de-bonding the carrier,recessing the molding layer from the second side of the molding layer,where the recessing exposes a second surface of the first dielectricstructure opposing the first surface of the first dielectric structure.In an embodiment, the method further includes forming a seconddielectric structure on the carrier, where the second dielectricstructure is made of a same dielectric material as the first dielectricstructure, where the conductive layer is formed over the seconddielectric structure, and where the conductive layer over the seconddielectric structure is electrically coupled between the conductivelines of the first redistribution structure and the conductive lines ofthe second redistribution structure.

In an embodiment, a semiconductor device includes a first die; a seconddie laterally spaced from the first die; a molding material, where thefirst die and the second die are surrounded by the molding material; aredistribution structure over a first side of the molding material,where a conductive line of the redistribution structure is exposed at asidewall of the redistribution structure; and a first conductive layeron sidewalls of the molding material and on a second side of the moldingmaterial opposing the first side, where the first conductive layer iselectrically connected to the conductive line of the redistributionstructure. In an embodiment, the semiconductor device further includes asecond conductive layer along sidewalls of the first die. In anembodiment, sidewalls of the second die are free of the secondconductive layer.

In an embodiment, a package includes a substrate; a connectorelectrically coupled to first conductive pads of the substrate, theconnector including a signal terminal and a ground terminal; and asemiconductor device electrically coupled to second conductive pads ofthe substrate, where the semiconductor device includes a first dieembedded in a molding material, the first die having a first conductivecoating on sidewalls of the first die; a redistribution structure over afirst side of the molding material, the redistribution structure havingconducive lines electrically coupled to the first die; a secondconductive coating along sidewalls of the molding material and a secondside of the molding material opposing the first side; and externalconnectors attached to the redistribution structure, where the externalconnectors includes a signal connector, a first ground connector, and asecond ground connector, where the signal connector is coupled to thesignal terminal by a conductive line of the substrate, where the firstground connector and the second ground connector are coupled to theground terminal by a first ground plane and a second ground plane of thesubstrate, respectively, where the conductive line is between the firstground plane and the second ground plane. In an embodiment, theconnector is a radio frequency (RF) connector.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A semiconductor device comprising: a first die; amolding material around the first die; a redistribution structure alonga first side of the molding material and along a first side of the firstdie, the redistribution structure being electrically coupled to thefirst die; a first conductive coating comprising a first portion thatextends along and contacts sidewalls of the first die, the first portionbeing disposed between the first die and the molding material; and asecond conductive coating extending along sidewalls of the moldingmaterial distal from the first die, along a second side of the moldingmaterial opposing the first side of the molding material, and along asecond side of the first die opposing the first side of the first die,wherein the molding material is between the first conductive coating andthe second conductive coating, wherein the first conductive coatingfurther comprises a second portion that extends along the second side ofthe molding material and contacts the second conductive coating.
 2. Thesemiconductor device of claim 1, wherein the second portion of the firstconductive coating merges with respective potions of the secondconductive coating to form a conductive region, wherein the conductiveregion has a thickness that is about twice that of the first conductivecoating or twice that of the second conductive coating.
 3. Thesemiconductor device of claim 1, further comprising a dielectric layerbetween the second side of the first die and the second conductivecoating, wherein the dielectric layer and the first die have a samewidth such that sidewalls of the dielectric layer are aligned withrespective sidewalls of the first die.
 4. The semiconductor device ofclaim 3, wherein a surface of the second portion of the first conductivecoating facing away from the redistribution structure is level with asurface of the dielectric layer facing away from the redistributionstructure.
 5. The semiconductor device of claim 1, wherein the firstconductive coating is electrically coupled to the first die by a firstvia of the redistribution structure, wherein the first via physicallycontacts the first conductive coating and a first die connector of thefirst die.
 6. The semiconductor device of claim 5, wherein the first viahas a first dimension along a first direction and has a second dimensionalong a second direction perpendicular to the first direction, thesecond dimension being larger than the first dimension, the firstdirection and the second direction defining a first plane parallel tothe first side of the molding material.
 7. The semiconductor device ofclaim 6, wherein the first die connector of the first die has anextension portion that extends toward the first conductive coating alonga second plane parallel to the first plane.
 8. The semiconductor deviceof claim 5, wherein the second conductive coating is electricallycoupled to a first conductive line of the redistribution structure,wherein the first conductive line is exposed at a sidewall of theredistribution structure.
 9. The semiconductor device of claim 8,wherein the first die connector is electrically coupled to a groundcontact pad of the first die, wherein the first conductive coating andthe second conductive coating are electrically coupled to the groundcontact pad.
 10. The semiconductor device of claim 5, wherein a secondvia of the redistribution structure physically contacts the firstconductive coating but does not physically contact the first die,wherein the second via is electrically coupled to a ground contact padof the first die.
 11. The semiconductor device of claim 1, furthercomprising a second die laterally adjacent to the first die, wherein themolding material surrounds the second die, and the redistributionstructure extends continuously from the first die to the second die,wherein the first conductive coating extends continuously from the firstdie to the second die.
 12. The semiconductor device of claim 5, whereinin a top view, the first via of the redistribution structure has anelongated shape, wherein a longitudinal axis of the elongated shapeextends along a direction from the first die connector of the first dietoward a sidewall of the first die.
 13. A semiconductor devicecomprising: a die embedded in a molding material; a redistributionstructure on a first side of the molding material; and anelectromagnetic interference (EMI) shield for the die, the EMI shieldcomprising: a first conductive coating on sidewalls of the die, whereinthe first conductive coating is electrically grounded by a via of theredistribution structure that electrically couples the first conductivecoating to a die connector of the die, wherein a surface of the viaclosest to the die is in physical contact with the first conductivecoating and the die connector of the die; and a second conductivecoating on exterior sidewalls of the molding material and on a secondside of the molding material opposing the first side of the moldingmaterial, wherein the first conductive coating is between the die andthe second conductive coating, wherein the second conductive coating iselectrically grounded by a conductive line of the redistributionstructure that is exposed at a sidewall of the redistribution structure.14. The semiconductor device of claim 13, wherein the via has anelongated shape in a top view, and wherein in the top view, alongitudinal axis of the elongated shape is along a direction from thedie connector to the first conductive coating.
 15. The semiconductordevice of claim 13, further comprising a dielectric layer between thedie and the second conductive coating, the dielectric layer having asame width as the die.
 16. The semiconductor device of claim 15, whereinthe first conductive coating further extends along the second side ofthe molding material and contacts the second conductive coating.
 17. Thesemiconductor device of claim 13, wherein the die connector of the diehas an extension portion that extends laterally toward a sidewall of thedie.
 18. A semiconductor device comprising: a die; a molding materialaround the die; a redistribution structure along a first side of themolding material and electrically coupled to a front side of the die; afirst conductive layer between the die and the molding material, thefirst conductive layer extending along sidewalls of the die and along asecond side of the molding material opposing the first side of themolding material, wherein a backside of the die is exposed by the firstconductive layer, wherein a first via of the redistribution structurephysically contacts the first conductive layer and a conductive pillarof the die; a second conductive layer along sidewalls of the moldingmaterial, along the second side of the molding material, and along thebackside of the die, wherein the molding material is between the firstconductive layer and the second conductive layer; and a dielectric layerbetween the second conductive layer and the die.
 19. The semiconductordevice of claim 18, wherein the first conductive layer comprises a firstportion along a semiconductor substrate of the die and comprises asecond portion along a dielectric material around the conductive pillarof the die, wherein the first portion and the second portion of thefirst conductive layer comprise different materials.
 20. Thesemiconductor device of claim 18, wherein the dielectric layer contactsthe backside of the die and the second conductive layer, and sidewallsof the dielectric layer are aligned with respective sidewalls of thedie.